If you want to answer that by saying, “Because speaking out wouldn’t accomplish anything,” okay. Words without the threat of U.S. military force behind them aren’t going to change a foreign government’s calculations about how to handle a popular uprising.

But we hammered Obama pretty hard in 2009 when he kept a low profile during Iran’s Green Revolution even though there was no prospect of American military intervention there. If nothing else, Trump reminding Beijing that the eyes of the world are upon Hong Kong may increase pressure on them to show restraint and increase pressure on European countries to punish China if a massacre ensues.

And the pundit-in-chief normally doesn’t need a strategic reason to spout off on Twitter about something. He’ll lash out gratuitously if he regards you as an enemy, as Anthony Scaramucci and Chris Cuomo have each been reminded within the past 24 hours or so. China happens to be Trump’s designated archenemy internationally, a rising superpower with whom we’re already locked in a deepening trade war. It is … not like him to pass on a chance to exploit an enemy’s embarrassment, but that’s what he’s doing right now by keeping a low profile about the massive protests.

And he’s doing it while prominent Democrats are getting out in front on the subject:

It’s not as if he’s said nothing about Hong Kong. It’s just that he’s been weak and vague even by the usual standards of his pronouncements on foreign policy. From last week:

Q Are you concerned by reports that the Chinese army may be preparing to intervene in Hong Kong against the demonstrators? And what do you say to the accusation that the U.S. is somehow behind these protests?

THE PRESIDENT: Well, something is probably happening with Hong Kong because when you look at, you know, what’s going on, they’ve had riots for a long period of time. And I don’t know what China’s attitude is. Somebody said that at some point they’re going to want to stop that. But that’s between Hong Kong and that’s between China, because Hong Kong is a part of China. They’ll have to deal with that themselves. They don’t need advice.

Way to take a stand, buddy. He was asked again about Hong Kong today and, well…

Does he have even a glancing awareness of what Hong Kong’s dispute with China is about? This is the sort of non-answer he stumbles through when he’s caught off-guard by a question and doesn’t know what to say about it. “It’s a tough situation. We’ll see what happens.”

He tweeted about it afterward. Not so much clarity here either:

There are two obvious possibilities for why he might be keeping a low profile. One: His staffers have advised him to do so, knowing that China would love to exploit American agitation on the protesters’ behalf to claim that the protests are some sort of CIA plot. They’re doing it already, in fact, as John noted earlier. Maybe, against all odds, POTUS has chosen to muzzle himself in this case because the old hands at the State Department and National Security Council have formally recommended that he do so.

Doesn’t seem like him, though. And if China’s already blaming America for the protests, how much harm could a little presidential rhetorical support do? If nothing else, Trump focusing world attention on Hong Kong might make Beijing think twice about pulling a Tiananmen 2.0.

Two: As much as he hates China, he hates mass protests more. Trump is an authoritarian and authoritarians naturally have difficulty cheering on popular uprisings even when it’s in their interest to do so. Remember, this is a guy who once said of the Tiananmen Square massacre:

Trump said he’d been “very unimpressed” with the Soviet Union.

“Their system is a disaster,” Trump said. “What you will see there soon is a revolution; the signs are all there with the demonstrations and picketing. Russia is out of control and the leadership knows it. That’s my problem with [former Soviet President Mikhail] Gorbachev. Not a firm enough hand.”

The future US president was then asked if he meant “firm hand as in China.”

“When the students poured into Tiananmen Square, the Chinese government almost blew it. Then they were vicious, they were horrible, but they put it down with strength,” Trump replied. “That shows you the power of strength. Our country is right now perceived as weak…as being spit on by the rest of the world.”

When people show their strength by massing in great numbers, the government needs to show its own “strength” by cracking heads. That’s the Trumpian view. He’s so devoted to it, in fact, that he once passed up an easy opportunity to criticize Obama when protests erupted in Hong Kong. Jeryl Bier dug up this old Trump tweet from 2014, when it would have been easy for POTUS to complain that Obama wasn’t doing enough to put pressure on China. Nope — hands off, said Trump to O at the time:

I’m morbidly curious to see how he’d react to tanks rolling in Hong Kong tomorrow. Probably he’d issue a pro forma written denunciation penned by John Bolton and then in his next Q&A with reporters start mumbling about China’s lamentable “strength” in restoring order. When the people become unruly, the great populist will imply, those in power need to put them back into line, however ugly that may be. We’ll see.

One other possibility: Trump is willing to start agitating on Hong Kong’s behalf but not until the shape of trade negotiations with China becomes clearer. If and when he becomes convinced that there’ll be no deal before 2020, he’ll let Beijing have it. But so long as a deal remains in the offing, he needs to be cool and bite his lip. America First, right? If speaking out about Hong Kong would piss off the Chinese to the point that they’d walk away from a trade deal, further damaging the U.S. economy, then he’ll keep quiet.

Although, given how he likes to talk about the damage the trade war is doing to China’s economy, he must believe that walking away isn’t an option for them. They need to make a deal before 2020. In which case, why not twist the knife by hyping their Hong Kong problem?

I’ll leave you with this, as an insight into how U.S. foreign policy personnel tend to deal with Trump’s views.